Such carriage arrangements are used in particular in machine tools that are used for the finishing of gear wheel blanks. These work pieces require indexing, i.e., recording their rotational position with the probe, to adjust a suitable relative position for the finishing between the work piece and the machine tool, for example a honing cutter. In doing so, generally the gear wheel blank forming the work piece is clamped on a rotationally drivable work spindle, which is supported on the first carriage.
For the indexing, the first carriage, which supports the work piece, is brought into its first position and the probe, which forms the indexing sensor, is advanced very close to the work piece by adjusting the second carriage, which carries the probe, into its measurement position. After the indexing, the second carriage must then be retracted into its rest position away from the measurement point so that the work piece on the first carriage can be transferred into the second position for finishing without said adjusting motion causing a collision between the probe and the work piece, the clamping device that clamps the work piece, or the first carriage which supports the work piece. This in particular also includes the case where the first carriage is first adjusted into its loading position, where the work piece is clamped, and only then is adjusted into its first position. It may be provided that during that time, the second carriage which carries the probe remains in its rest position to avoid a potential collision, for example with an interfering contour of the clamped work piece, and is only then adjusted to its measuring point near the work piece now in the first position.
These adjusting motions are conventionally realized with an electric, pneumatic or hydraulic drive. To ensure that the probe is not in the collision reach, position sensors request the instantaneous position of the second carriage, which carries the probe. The adjusting motion of the first carriage, which carries the work piece, from its first position where the indexing was performed and its second position, where the work piece is brought into engagement with the machine tool, is started only after the position sensors that monitor the second carriage issue a release signal. Thus, retracting the probe from its measuring point and advancing the work piece into its second position occur in a time interval. In a serial sequence of retracting the second carriage and advancing the first carriage, this requires an idle time that corresponds to the total of the time required for the adjusting motion of the second carriage between the measuring point and the rest position and the adjusting motion of the first carriage between the first and the second position.
An object to be attained by the invention is to develop a carriage arrangement of the type described above in such a way as to shorten said idle times.